inorganic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

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ISSN: 2056-9890

Redetermination of MoPt3Si4 from single-crystal data

aInstitut Jean Lamour, UMR 7198, Département 2, Université Henri Poincaré, Nancy Université, Faculté des Sciences et Techniques, BP 239, 54506 Vandoeuvre les Nancy CEDEX, France
*Correspondence e-mail: michel.francois@lcsm.uhp-nancy.fr

(Received 5 November 2010; accepted 27 December 2010; online 22 January 2011)

The crystal structure of molybdenum triplatinum tetrasilicide, MoPt3Si4, determined previously from powder diffraction data [Joubert et al. (2010[Joubert, J.-M., Tokaychuk, Ya. & Cerny, R. (2010). J. Solid State Chem. 183, 173-179.]). J. Solid State Chem. 183, 173–179], has been redetermined using a single crystal synthesized from the elements by high-frequency melting. The redetermination provides more precise geometrical data and also anisotropic displacement parameters. The crystal structure can be considered to be derived from the PtSi structure type with an ordered substitution of Pt by Mo atoms, but leading to a very distorted Si network compared to the parent structure. Mo and Pt exhibit different coordination polyhedra. These are based on bicapped-square anti­prisms, but with two additional vertices in cis positions for Mo, whereas they are in trans positions for Pt (as in PtSi). The coordination polyhedra for three of the Si atoms can be considered as highly deformed square anti­prisms (as in PtSi), while the fourth Si atom has a bicapped trigonal–prismatic coordination geometry.

Related literature

For general background to molybdenum silicides, see: Littner (2003[Littner, A. (2003). These de Doctorat, Université Henri Poincaré de Nancy, France.]); Benarchid et al. (2009[Benarchid, Y., David, N., Fiorani, J.-M. & Vilasi, M. (2009). Thermochim. Acta, 494, 26-29.]); Bernard et al. (2010[Bernard, F., Cabouro, G., Le Gallet, S., Chevalier, S., Gaffet, E. & Grin, Yu. (2010). Ceram. Trans. 209, 357-365.]); Cabouro et al. (2007[Cabouro, G., Chevalier, S., Gaffet, E., Vrel, E., Boudet, N. & Bernard, F. (2007). Acta Mater. 55, 6051-6063.], 2008[Cabouro, G., Chevalier, S., Gaffet, E., Grin, Yu. & Bernard, F. (2008). J. Alloys Compd, 465, 344-355.]); Fitzer (1955[Fitzer, E. (1955). Molybdenum disilicide as high-temperature material, Plansee Proc., 2nd Seminar, Reutte/Tyrol (1955), pp. 56-79.]); Knittel et al. (2010[Knittel, S., Mathieu, S. & Vilasi, M. (2010). Intermetallics, 18, 2267-2274.]). For the structure determination of the title compound from standard X-ray powder diffraction data, see: Joubert et al. (2010[Joubert, J.-M., Tokaychuk, Ya. & Cerny, R. (2010). J. Solid State Chem. 183, 173-179.]). For the PAP correction program, see: Pouchou & Pichoir (1984[Pouchou, J. L. & Pichoir, F. (1984). Recherche Aérospatiale, 5, 349-351.]).

Experimental

Crystal data
  • MoPt3Si4

  • Mr = 793.57

  • Orthorhombic, P n m a

  • a = 5.5121 (2) Å

  • b = 3.4951 (1) Å

  • c = 24.3078 (7) Å

  • V = 468.30 (3) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 92.80 mm−1

  • T = 297 K

  • 0.12 × 0.03 × 0.03 mm

Data collection
  • Bruker APEXII QUAZAR CCD diffractometer

  • Absorption correction: multi-scan (SADABS; Bruker, 2004[Bruker (2004). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.031, Tmax = 0.174

  • 9779 measured reflections

  • 1060 independent reflections

  • 955 reflections with I > 2σ(I)

  • Rint = 0.040

Refinement
  • R[F2 > 2σ(F2)] = 0.029

  • wR(F2) = 0.067

  • S = 1.41

  • 1060 reflections

  • 50 parameters

  • Δρmax = 2.16 e Å−3

  • Δρmin = −3.81 e Å−3

Table 1
Selected bond lengths (Å)

Pt1—Si3i 2.406 (3)
Pt1—Pt1ii 2.9119 (6)
Pt2—Si1iii 2.387 (3)
Pt2—Mo1iv 2.9331 (10)
Pt3—Si3 2.405 (2)
Pt3—Pt2 2.8874 (5)
Mo1—Si4 2.535 (2)
Mo1—Pt2iii 2.9331 (10)
Si1—Pt2iv 2.387 (3)
Si1—Si2 2.711 (3)
Si2—Pt3 2.466 (3)
Si2—Si1 2.711 (3)
Si3—Pt1v 2.590 (2)
Si3—Si3vi 2.807 (5)
Si4—Pt2v 2.407 (2)
Si4—Si4vii 3.012 (5)
Symmetry codes: (i) -x+1, -y, -z+1; (ii) -x+1, -y+1, -z+1; (iii) x-1, y, z; (iv) x+1, y, z; (v) x, y-1, z; (vi) -x, -y, -z+1; (vii) [x-{\script{1\over 2}}, y, -z+{\script{3\over 2}}].

Data collection: APEX2 (Bruker, 2004[Bruker (2004). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2004[Bruker (2004). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: DIAMOND (Brandenburg, 1999[Brandenburg, K. (1999). DIAMOND. Crystal Impact GbR, Bonn, Germany.]) and ORTEP-3 (Farrugia, 1997[Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565.]); software used to prepare material for publication: SHELXL97.

Supporting information


Comment top

Interest for studying the Mo—MP—Si (MP = Pt, Ru) system follows from the attractive properties of MoSi2 regarding high-temperature oxidation. But early in the past, the first studies performed by Fitzer (1955) mentioned the poor behaviour of this material under oxidizing atmosphere at moderate temperatures (300–600°C) due to a catastrophic degradation, the so-called "pest phenomenon". Consequently, one of the challenges for application of MoSi2 is to control the pest oxidation by adding alloying elements (Ru, Pt, B, Al, Ge, Y, Ti, Zr, Ta) (Littner, 2003, Benarchid et al. 2009) and/or by controlling the microstructure. Recently, the optimization of the microstructure led to fully densified materials showing dramatically improved oxidation performance of MoSi2 (Cabouro et al., 2007, Cabouro et al., 2008, Knittel et al., 2010), Bernard et al., 2010. In the course of our studies focused on the evaluation of the effect of elemental substitutions, we studied the isothermal section of the ternary phase diagram Mo—Pt—Si at 1423 K. Two new phases of composition MoPt2Si3 and MoPt3Si4 were identified (Littner, 2003), and MoPt3Si4 was indexed in the orthorhombic system: a = 5.5096 Å, b = 3.493 Å, c = 24.294 Å. The structure of MoPt3Si4 was recently published by Joubert et al. (2010), from powder X-ray diffraction data. It turned out that the MoPt3Si4 structure can be derived from PtSi by an ordered substitution of Pt by Mo. The atomic arrangement along the c axis leads to a fourfold superstructure, with c(MoPt3Si4) = 4 × c(PtSi). Our analysis based on single-crystal data confirms the previous results but yields more accurate atomic positions, approximately by one order of magnitude. Additionally, this also allows determination of anisotropic displacement parameters (Fig. 1). Fig. 2 shows the coordination polyhedra. The coordination number for each d metal is 10, for Si it is 8. Mo and Pt exhibit different coordination polyhedra. In both cases, these are based on bicapped-square antiprisms, but with two additional vertices in cis-positions for Mo whereas they are in trans-positions for Pt (as in PtSi). The coordination polyhedra for Si1, Si2 and Si3 atoms can be considered as highly deformed square antiprisms (as in PtSi), while Si4 has a bicapped trigonal prismatic coordination geometry. Shortest and longest interatomic distances for each coordination polyedra are reported in Table 1. The shortest distances found for Mo—Si and Pt—Si are 2.535 (2) Å and of 2.387 (3) Å respectively. These may be compared to the values given by Joubert et al. (2010), namely 2.463 Å and 2.355 Å.

Figure 3 also emphasizes that the corrugated ribbons formed by the silicon sub-network and expanded along the c axis are greatly distorted compared to the PtSi parent structure.

Related literature top

For general background to molybden silicides, see: Littner (2003); Benarchid et al. (2009); Bernard et al. (2010); Cabouro et al. (2007, 2008); Fitzer (1955); Knittel et al. (2010). For the structure determination of the title compound from standard powder diffraction data, see: Joubert et al. (2010).

For the PAP correction program, see: Pouchou & Pichoir (1984).

Experimental top

Metal powders with nominal purities > 99.9 (Pt sponge 270 mesh - Engelhard - Clal, Si and Mo 325 mesh: Cerac) were mixed in different atomic ratios corresponding to alloys belonging to the MoSi2—Mo5Si3—PtSi domain. An ingot was prepared by high frequency melting, and stabilized in a thermodynamic equilibrium for 100 h at 1150°C under argon. Single crystals of Pt3MoSi4 were directly isolated from the crushed ingot. A part of the ingot was embedded in an epoxy resin, polished and microanalyzed by an electron probe (SX 50 CAMECA, - PAP correction program (Pouchou & Pichoir, 1984). The EPMA composition corresponds, within the accuracy of the measurement, to that obtained by the structural determination.

Refinement top

Maximum residual electron density: highest peak 2.16 found at 0.75 Å from Pt2 and minimum residual electron density: highest hole -3.81 found at 1.22 Å from Si4

Computing details top

Data collection: APEX2 (Bruker, 2004); cell refinement: SAINT (Bruker, 2004); data reduction: SAINT (Bruker, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 1999) and ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. Plot of the asymmetric unit of MoPt3Si4. The displacement ellipsoids are drawn at the 75% probability level. Atoms are bonded for interatomic distances lower than 3.1 Å.
[Figure 2] Fig. 2. The unit cell and the coordination polyhedra of the atoms in the structure of MoPt3Si4. Si in blue, Pt in light grey, Mo in yellow.
[Figure 3] Fig. 3. Corrugated ribbons from Si atoms in the structure of PtSi and MoPt3Si4.
Molybdenum triplatinum tetrasilicide top
Crystal data top
MoPt3Si4Dx = 11.256 Mg m3
Mr = 793.57Melting point: 1503 K
Orthorhombic, PnmaMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2nCell parameters from 4246 reflections
a = 5.5121 (2) Åθ = 3.4–33.7°
b = 3.4951 (1) ŵ = 92.80 mm1
c = 24.3078 (7) ÅT = 297 K
V = 468.30 (3) Å3Needle, metallic colourless
Z = 40.12 × 0.03 × 0.03 mm
F(000) = 1328
Data collection top
Bruker APEXII QUAZAR CCD
diffractometer
1060 independent reflections
Radiation source: ImuS955 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.040
ω scansθmax = 33.7°, θmin = 1.7°
Absorption correction: multi-scan
(SADABS; Bruker, 2004)
h = 88
Tmin = 0.031, Tmax = 0.174k = 55
9779 measured reflectionsl = 3437
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.029 w = 1/[σ2(Fo2) + (0.0069P)2 + 14.4673P]
where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.067(Δ/σ)max = 0.001
S = 1.41Δρmax = 2.16 e Å3
1060 reflectionsΔρmin = 3.81 e Å3
50 parametersExtinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
0 restraintsExtinction coefficient: 0.00129 (7)
Crystal data top
MoPt3Si4V = 468.30 (3) Å3
Mr = 793.57Z = 4
Orthorhombic, PnmaMo Kα radiation
a = 5.5121 (2) ŵ = 92.80 mm1
b = 3.4951 (1) ÅT = 297 K
c = 24.3078 (7) Å0.12 × 0.03 × 0.03 mm
Data collection top
Bruker APEXII QUAZAR CCD
diffractometer
1060 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2004)
955 reflections with I > 2σ(I)
Tmin = 0.031, Tmax = 0.174Rint = 0.040
9779 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0290 restraints
wR(F2) = 0.067 w = 1/[σ2(Fo2) + (0.0069P)2 + 14.4673P]
where P = (Fo2 + 2Fc2)/3
S = 1.41Δρmax = 2.16 e Å3
1060 reflectionsΔρmin = 3.81 e Å3
50 parameters
Special details top

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
Pt10.50285 (7)0.25000.547907 (16)0.00783 (11)
Pt20.00468 (7)0.25000.669289 (16)0.00688 (11)
Pt30.00210 (7)0.25000.574730 (17)0.00783 (11)
Mo10.49497 (15)0.25000.71035 (4)0.00562 (16)
Si10.6616 (6)0.25000.60935 (12)0.0071 (5)
Si20.3216 (6)0.25000.64573 (12)0.0072 (5)
Si30.1790 (6)0.25000.51984 (12)0.0076 (5)
Si40.1678 (6)0.75000.72502 (12)0.0071 (5)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Pt10.00828 (19)0.00729 (18)0.00793 (19)0.0000.00011 (13)0.000
Pt20.00732 (18)0.00574 (16)0.00759 (19)0.0000.00034 (13)0.000
Pt30.00835 (18)0.00728 (17)0.00787 (18)0.0000.00006 (13)0.000
Mo10.0068 (3)0.0044 (3)0.0057 (3)0.0000.0003 (3)0.000
Si10.0086 (11)0.0063 (11)0.0064 (12)0.0000.0006 (10)0.000
Si20.0092 (12)0.0055 (12)0.0068 (12)0.0000.0021 (10)0.000
Si30.0090 (12)0.0063 (12)0.0075 (11)0.0000.0004 (10)0.000
Si40.0099 (12)0.0033 (11)0.0082 (12)0.0000.0006 (10)0.000
Geometric parameters (Å, º) top
Pt1—Si3i2.406 (3)Mo1—Si1v2.602 (3)
Pt1—Si12.460 (2)Mo1—Pt2xi2.9256 (10)
Pt1—Si1ii2.460 (2)Mo1—Pt22.929 (1)
Pt1—Si22.579 (3)Mo1—Pt2v2.9331 (10)
Pt1—Si32.590 (2)Si1—Pt2iii2.387 (3)
Pt1—Si3ii2.590 (2)Si1—Pt1vi2.460 (2)
Pt1—Pt3iii2.8281 (6)Si1—Pt12.460 (2)
Pt1—Pt32.8362 (6)Si1—Mo1iii2.602 (3)
Pt1—Pt1i2.9119 (6)Si1—Pt3iii2.699 (2)
Pt1—Pt1iv2.9119 (6)Si1—Pt3xiii2.699 (2)
Pt2—Si1v2.387 (3)Si1—Si2vi2.711 (3)
Pt2—Si4ii2.407 (2)Si1—Si22.711 (3)
Pt2—Si42.407 (2)Si2—Pt32.466 (3)
Pt2—Si22.536 (2)Si2—Pt2ii2.536 (2)
Pt2—Si2vi2.536 (2)Si2—Pt22.536 (2)
Pt2—Pt3vi2.8874 (5)Si2—Mo1xiv2.558 (2)
Pt2—Pt32.8874 (5)Si2—Mo1iii2.558 (2)
Pt2—Mo1vii2.9255 (10)Si2—Pt12.579 (3)
Pt2—Mo12.9294 (10)Si2—Si1ii2.711 (3)
Pt2—Mo1iii2.9331 (10)Si2—Si12.711 (3)
Pt3—Si32.405 (2)Si3—Pt1vi2.590 (2)
Pt3—Si3ii2.405 (2)Si3—Pt12.590 (2)
Pt3—Si22.466 (3)SI3—Pt32.405 (2)
Pt3—Si3viii2.506 (3)Si3—Pt3vi2.405 (2)
Pt3—Si1v2.699 (2)Si3—Pt1i2.406 (3)
Pt3—Si1ix2.699 (2)Si3—Pt3viii2.506 (3)
Pt3—Pt1v2.8281 (6)Si3—Si3xv2.807 (5)
Pt3—Pt12.836 (1)Si3—Si3viii2.807 (5)
Pt3—Pt2ii2.8874 (5)Si4—Pt2vi2.407 (2)
Pt3—Pt22.8874 (5)Si4—Pt22.407 (2)
Mo1—Si42.535 (2)Si4—Mo1vii2.535 (2)
Mo1—Si4ii2.537 (2)Si4—Mo1xvi2.535 (2)
Mo1—Si4x2.535 (2)Si4—Mo1vi2.537 (2)
Mo1—Si4xi2.535 (2)Si4—Mo12.536 (2)
Mo1—Si2xii2.558 (2)Si4—Si4vii3.012 (5)
Mo1—Si2v2.558 (2)Si4—Si4xi3.012 (5)
Si3i—Pt1—Si198.99 (9)Si4ii—Mo1—Si487.10 (10)
Si3i—Pt1—Si1ii98.99 (9)Si4x—Mo1—Si2xii134.65 (10)
Si1—Pt1—Si1ii90.54 (10)Si4xi—Mo1—Si2xii76.18 (8)
Si3i—Pt1—Si2155.99 (10)Si4ii—Mo1—Si2xii146.93 (10)
Si1—Pt1—Si265.04 (8)Si4—Mo1—Si2xii84.07 (8)
Si1ii—Pt1—Si265.04 (8)Si4x—Mo1—Si2v76.18 (8)
Si3i—Pt1—Si3108.80 (8)Si4xi—Mo1—Si2v134.65 (10)
Si1—Pt1—Si385.75 (8)Si4ii—Mo1—Si2v84.07 (8)
Si1ii—Pt1—Si3152.21 (10)Si4—Mo1—Si2v146.93 (10)
Si2—Pt1—Si388.61 (8)Si2xii—Mo1—Si2v86.18 (9)
Si3i—Pt1—Si3ii108.80 (8)Si4x—Mo1—Si1v135.16 (5)
Si1—Pt1—Si3ii152.21 (10)Si4xi—Mo1—Si1v135.16 (5)
Si1ii—Pt1—Si3ii85.75 (8)Si4ii—Mo1—Si1v84.07 (9)
Si2—Pt1—Si3ii88.61 (8)Si4—Mo1—Si1v84.08 (9)
Si3—Pt1—Si3ii84.88 (9)Si2xii—Mo1—Si1v63.37 (8)
Si3i—Pt1—Pt3iii56.52 (7)Si2v—Mo1—Si1v63.37 (8)
Si1—Pt1—Pt3iii60.91 (7)Si4x—Mo1—Pt2xi51.70 (6)
Si1ii—Pt1—Pt3iii60.91 (7)Si4xi—Mo1—Pt2xi51.70 (6)
Si2—Pt1—Pt3iii99.47 (7)Si4ii—Mo1—Pt2xi81.95 (7)
Si3—Pt1—Pt3iii137.02 (5)Si4—Mo1—Pt2xi81.94 (7)
Si3ii—Pt1—Pt3iii137.02 (5)Si2xii—Mo1—Pt2xi127.87 (6)
Si3i—Pt1—Pt3150.09 (8)Si2v—Mo1—Pt2xi127.87 (6)
Si1—Pt1—Pt3101.93 (7)Si1v—Mo1—Pt2xi160.67 (8)
Si1ii—Pt1—Pt3101.93 (7)Si4x—Mo1—Pt2124.35 (7)
Si2—Pt1—Pt353.91 (7)Si4xi—Mo1—Pt2124.35 (7)
Si3—Pt1—Pt352.39 (6)Si4ii—Mo1—Pt251.64 (6)
Si3ii—Pt1—Pt352.39 (6)Si4—Mo1—Pt251.64 (6)
Pt3iii—Pt1—Pt3153.38 (2)Si2xii—Mo1—Pt299.35 (7)
Si3i—Pt1—Pt1i57.34 (5)Si2v—Mo1—Pt299.35 (7)
Si1—Pt1—Pt1i93.62 (5)Si1v—Mo1—Pt250.71 (7)
Si1ii—Pt1—Pt1i156.33 (7)Pt2xi—Mo1—Pt2109.96 (3)
Si2—Pt1—Pt1i137.15 (4)Si4x—Mo1—Pt2v81.81 (7)
Si3—Pt1—Pt1i51.45 (7)Si4xi—Mo1—Pt2v81.81 (7)
Si3ii—Pt1—Pt1i100.77 (6)Si4ii—Mo1—Pt2v135.76 (5)
Pt3iii—Pt1—Pt1i101.239 (19)Si4—Mo1—Pt2v135.76 (5)
Pt3—Pt1—Pt1i99.983 (19)Si2xii—Mo1—Pt2v54.50 (6)
Si3i—Pt1—Pt1iv57.34 (5)Si2v—Mo1—Pt2v54.50 (6)
Si1—Pt1—Pt1iv156.33 (7)Si1v—Mo1—Pt2v89.47 (7)
Si1ii—Pt1—Pt1iv93.62 (5)Pt2xi—Mo1—Pt2v109.86 (3)
Si2—Pt1—Pt1iv137.15 (4)Pt2—Mo1—Pt2v140.18 (4)
Si3—Pt1—Pt1iv100.77 (6)Pt2iii—Si1—Pt1130.73 (7)
Si3ii—Pt1—Pt1iv51.45 (7)Pt2iii—Si1—Pt1vi130.73 (7)
Pt3iii—Pt1—Pt1iv101.239 (19)Pt1—Si1—Pt1vi90.54 (10)
Pt3—Pt1—Pt1iv99.983 (19)Pt2iii—Si1—Mo1iii71.76 (8)
Pt1i—Pt1—Pt1iv73.760 (19)Pt1—Si1—Mo1iii117.05 (9)
Si1v—Pt2—Si4ii91.76 (9)Pt1vi—Si1—Mo1iii117.05 (9)
Si1v—Pt2—Si491.76 (9)Pt2iii—Si1—Pt3iii68.87 (7)
Si4ii—Pt2—Si493.12 (11)Pt1—Si1—Pt3iii66.30 (4)
Si1v—Pt2—Si2114.06 (8)Pt1vi—Si1—Pt3iii121.20 (11)
Si4ii—Pt2—Si284.19 (8)Mo1iii—Si1—Pt3iii121.65 (8)
Si4—Pt2—Si2154.07 (10)Pt2iii—Si1—Pt3xiii68.87 (7)
Si1v—Pt2—Si2vi114.06 (8)Pt1—Si1—Pt3xiii121.20 (11)
Si4ii—Pt2—Si2vi154.07 (10)Pt1vi—Si1—Pt3xiii66.30 (4)
Si4—Pt2—Si2vi84.19 (8)Mo1iii—Si1—Pt3xiii121.65 (8)
Si2—Pt2—Si2vi87.10 (10)Pt3iii—Si1—Pt3xiii80.71 (9)
Si1v—Pt2—Pt3vi60.68 (5)Pt2iii—Si1—Si2110.40 (11)
Si4ii—Pt2—Pt3vi152.32 (7)Pt1—Si1—Si259.61 (7)
Si4—Pt2—Pt3vi90.38 (6)Pt1vi—Si1—Si2114.21 (13)
Si2—Pt2—Pt3vi103.92 (6)Mo1iii—Si1—Si257.52 (8)
Si2vi—Pt2—Pt3vi53.60 (6)Pt3iii—Si1—Si299.50 (4)
Si1v—Pt2—Pt360.68 (5)Pt3xiii—Si1—Si2179.13 (14)
Si4ii—Pt2—Pt390.38 (6)Pt2iii—Si1—Si2vi110.40 (11)
Si4—Pt2—Pt3152.32 (7)Pt1—Si1—Si2vi114.21 (13)
Si2—Pt2—Pt353.60 (6)Pt1vi—Si1—Si2vi59.61 (7)
Si2vi—Pt2—Pt3103.93 (6)Mo1iii—Si1—Si2vi57.52 (8)
Pt3vi—Pt2—Pt374.490 (14)Pt3iii—Si1—Si2vi179.13 (14)
Si1v—Pt2—Mo1vii127.65 (7)Pt3xiii—Si1—Si2vi99.50 (4)
Si4ii—Pt2—Mo1vii55.76 (6)Si2—Si1—Si2vi80.27 (12)
Si4—Pt2—Mo1vii55.76 (6)Pt3—Si2—Pt2ii70.50 (7)
Si2—Pt2—Mo1vii103.02 (7)Pt3—Si2—Pt270.50 (7)
Si2vi—Pt2—Mo1vii103.02 (7)Pt2ii—Si2—Pt287.10 (10)
Pt3vi—Pt2—Mo1vii142.754 (7)Pt3—Si2—Mo1xiv135.41 (6)
Pt3—Pt2—Mo1vii142.754 (7)Pt2ii—Si2—Mo1xiv70.30 (5)
Si1v—Pt2—Mo157.54 (7)Pt2—Si2—Mo1xiv127.17 (12)
Si4ii—Pt2—Mo155.73 (7)Pt3—Si2—Mo1iii135.41 (6)
Si4—Pt2—Mo155.73 (7)Pt2ii—Si2—Mo1iii127.17 (12)
Si2—Pt2—Mo1136.42 (5)Pt2—Si2—Mo1iii70.30 (5)
Si2vi—Pt2—Mo1136.42 (5)Mo1xiv—Si2—Mo1iii86.17 (9)
Pt3vi—Pt2—Mo1105.463 (19)Pt3—Si2—Pt168.37 (8)
Pt3—Pt2—Mo1105.463 (19)Pt2ii—Si2—Pt1118.36 (8)
Mo1vii—Pt2—Mo170.12 (2)Pt2—Si2—Pt1118.36 (8)
Si1v—Pt2—Mo1iii162.29 (8)Mo1xiv—Si2—Pt1114.39 (9)
Si4ii—Pt2—Mo1iii100.36 (8)Mo1iii—Si2—Pt1114.39 (9)
Si4—Pt2—Mo1iii100.36 (8)Pt3—Si2—Si1ii105.40 (11)
Si2—Pt2—Mo1iii55.20 (6)Pt2ii—Si2—Si1ii96.07 (4)
Si2vi—Pt2—Mo1iii55.20 (6)Pt2—Si2—Si1ii173.71 (13)
Pt3vi—Pt2—Mo1iii105.996 (19)Mo1xiv—Si2—Si1ii59.11 (7)
Pt3—Pt2—Mo1iii105.996 (19)Mo1iii—Si2—Si1ii111.55 (13)
Mo1vii—Pt2—Mo1iii70.06 (2)Pt1—Si2—Si1ii55.35 (8)
Mo1—Pt2—Mo1iii140.18 (4)Pt3—Si2—Si1105.40 (11)
Si3—Pt3—Si3ii93.20 (11)Pt2ii—Si2—Si1173.71 (13)
Si3—Pt3—Si295.67 (9)Pt2—Si2—Si196.07 (4)
Si3ii—Pt3—Si295.67 (9)Mo1xiv—Si2—Si1111.55 (13)
Si3—Pt3—Si3viii69.67 (9)Mo1iii—Si2—Si159.11 (7)
Si3ii—Pt3—Si3viii69.67 (9)Pt1—Si2—Si155.35 (8)
Si2—Pt3—Si3viii157.89 (10)Si1ii—Si2—Si180.27 (12)
Si3—Pt3—Si1v89.11 (7)Pt3—Si3—Pt3vi93.20 (11)
Si3ii—Pt3—Si1v157.71 (9)Pt3—Si3—Pt1i132.47 (6)
Si2—Pt3—Si1v106.16 (8)Pt3vi—Si3—Pt1i132.47 (6)
Si3viii—Pt3—Si1v90.52 (8)Pt3—Si3—Pt3viii110.33 (9)
Si3—Pt3—Si1ix157.72 (9)Pt3vi—Si3—Pt3viii110.33 (9)
Si3ii—Pt3—Si1ix89.11 (7)Pt1i—Si3—Pt3viii70.27 (8)
Si2—Pt3—Si1ix106.16 (8)Pt3—Si3—Pt1vi128.58 (13)
Si3viii—Pt3—Si1ix90.52 (8)Pt3vi—Si3—Pt1vi69.08 (4)
Si1v—Pt3—Si1ix80.71 (9)Pt1i—Si3—Pt1vi71.20 (7)
Si3—Pt3—Pt1v105.46 (7)Pt3viii—Si3—Pt1vi121.08 (9)
Si3ii—Pt3—Pt1v105.46 (7)Pt3—Si3—Pt169.08 (4)
Si2—Pt3—Pt1v148.91 (8)Pt3vi—Si3—Pt1128.58 (13)
Si3viii—Pt3—Pt1v53.20 (7)Pt1i—Si3—Pt171.20 (7)
Si1v—Pt3—Pt1v52.79 (6)Pt3viii—Si3—Pt1121.08 (9)
Si1ix—Pt3—Pt1v52.79 (6)Pt1vi—Si3—Pt184.88 (9)
Si3—Pt3—Pt158.53 (7)Pt3—Si3—Si3xv110.98 (16)
Si3ii—Pt3—Pt158.53 (7)Pt3vi—Si3—Si3xv56.86 (7)
Si2—Pt3—Pt157.71 (7)Pt1i—Si3—Si3xv106.10 (14)
Si3viii—Pt3—Pt1100.18 (7)Pt3viii—Si3—Si3xv53.47 (10)
Si1v—Pt3—Pt1138.45 (5)Pt1vi—Si3—Si3xv98.92 (3)
Si1ix—Pt3—Pt1138.45 (5)Pt1—Si3—Si3xv174.46 (16)
Pt1v—Pt3—Pt1153.38 (2)Pt3—Si3—Si3viii56.86 (7)
Si3—Pt3—Pt2ii151.56 (8)Pt3vi—Si3—Si3viii110.98 (16)
Si3ii—Pt3—Pt2ii89.99 (6)Pt1i—Si3—Si3viii106.10 (14)
Si2—Pt3—Pt2ii55.90 (5)Pt3viii—Si3—Si3viii53.47 (10)
Si3viii—Pt3—Pt2ii137.07 (3)Pt1vi—Si3—Si3viii174.46 (16)
Si1v—Pt3—Pt2ii98.46 (5)Pt1—Si3—Si3viii98.92 (3)
Si1ix—Pt3—Pt2ii50.46 (6)Si3xv—Si3—Si3viii77.02 (16)
Pt1v—Pt3—Pt2ii100.856 (15)Pt2—Si4—Pt2vi93.11 (11)
Pt1—Pt3—Pt2ii100.265 (15)Pt2—Si4—Mo1vii72.54 (5)
Si3—Pt3—Pt289.99 (6)Pt2vi—Si4—Mo1vii134.49 (14)
Si3ii—Pt3—Pt2151.57 (8)Pt2—Si4—Mo1xvi134.49 (14)
Si2—Pt3—Pt255.90 (5)Pt2vi—Si4—Mo1xvi72.54 (5)
Si3viii—Pt3—Pt2137.07 (3)Mo1vii—Si4—Mo1xvi87.14 (10)
Si1v—Pt3—Pt250.46 (6)Pt2—Si4—Mo1vi134.58 (13)
Si1ix—Pt3—Pt298.46 (5)Pt2vi—Si4—Mo1vi72.63 (4)
Pt1v—Pt3—Pt2100.855 (15)Mo1vii—Si4—Mo1vi146.00 (13)
Pt1—Pt3—Pt2100.265 (15)Mo1xvi—Si4—Mo1vi83.07 (4)
Pt2ii—Pt3—Pt274.490 (14)Pt2—Si4—Mo172.63 (4)
Si4x—Mo1—Si4xi87.14 (10)Pt2vi—Si4—Mo1134.58 (13)
Si4x—Mo1—Si4ii72.85 (5)Mo1vii—Si4—Mo183.07 (4)
Si4xi—Mo1—Si4ii130.91 (7)Mo1xvi—Si4—Mo1146.01 (13)
Si4x—Mo1—Si4130.91 (6)Mo1vi—Si4—Mo187.10 (10)
Si4xi—Mo1—Si472.85 (5)
Symmetry codes: (i) x+1, y, z+1; (ii) x, y+1, z; (iii) x+1, y, z; (iv) x+1, y+1, z+1; (v) x1, y, z; (vi) x, y1, z; (vii) x+1/2, y, z+3/2; (viii) x, y, z+1; (ix) x1, y+1, z; (x) x1/2, y+1, z+3/2; (xi) x1/2, y, z+3/2; (xii) x1, y1, z; (xiii) x+1, y1, z; (xiv) x+1, y+1, z; (xv) x, y1, z+1; (xvi) x+1/2, y1, z+3/2.

Experimental details

Crystal data
Chemical formulaMoPt3Si4
Mr793.57
Crystal system, space groupOrthorhombic, Pnma
Temperature (K)297
a, b, c (Å)5.5121 (2), 3.4951 (1), 24.3078 (7)
V3)468.30 (3)
Z4
Radiation typeMo Kα
µ (mm1)92.80
Crystal size (mm)0.12 × 0.03 × 0.03
Data collection
DiffractometerBruker APEXII QUAZAR CCD
diffractometer
Absorption correctionMulti-scan
(SADABS; Bruker, 2004)
Tmin, Tmax0.031, 0.174
No. of measured, independent and
observed [I > 2σ(I)] reflections
9779, 1060, 955
Rint0.040
(sin θ/λ)max1)0.781
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.029, 0.067, 1.41
No. of reflections1060
No. of parameters50
w = 1/[σ2(Fo2) + (0.0069P)2 + 14.4673P]
where P = (Fo2 + 2Fc2)/3
Δρmax, Δρmin (e Å3)2.16, 3.81

Computer programs: APEX2 (Bruker, 2004), SAINT (Bruker, 2004), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), DIAMOND (Brandenburg, 1999) and ORTEP-3 (Farrugia, 1997).

Selected bond lengths (Å) top
Pt1—Si3i2.406 (3)Si1—Pt2iv2.387 (3)
Pt1—Pt1ii2.9119 (6)Si1—Si22.711 (3)
Pt2—Si1iii2.387 (3)Si2—Pt32.466 (3)
Pt2—Mo1iv2.9331 (10)Si2—Si12.711 (3)
Pt3—Si32.405 (2)Si3—Pt1v2.590 (2)
Pt3—Pt22.8874 (5)Si3—Si3vi2.807 (5)
Mo1—Si42.535 (2)Si4—Pt2v2.407 (2)
Mo1—Pt2iii2.9331 (10)Si4—Si4vii3.012 (5)
Symmetry codes: (i) x+1, y, z+1; (ii) x+1, y+1, z+1; (iii) x1, y, z; (iv) x+1, y, z; (v) x, y1, z; (vi) x, y, z+1; (vii) x1/2, y, z+3/2.
 

Acknowledgements

We thank Dr Holger Ott (Bruker AXS GmbH, Karlsruhe, Germany) for the data collection and the 'Service Commun de Microanalyse' (Faculté des Sciences et Techniques, Vandoeuvre les Nancy, France).

References

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